1. Field of the Invention
The present invention relates to a vehicle with a cabin.
2. Description of the Related Art
Known in the art are a vehicle with a cabin as disclosed in Japanese Laid-open Patent Application No. 2000-233688, for example, in which the cabin is supported via a vibration isolation member on the upper surface side of a cabin bracket that is extended in the left and right directions from a transmission case, and a vehicle with a cabin as disclosed in Japanese Laid-open Patent Application No. 2001-163267, for example, in which the cabin is supported via a vibration isolation member on the upper surface side of a cabin bracket that is extended in the left and right directions from a clutch housing.
In the conventional vehicle with a cabin disclosed in Japanese Laid-open Patent Application No. 2000-233688, the generation of a muffled noise is prevented by a configuration in which a damping mass is provided, and the resonance frequency of air inside the cabin and the oscillation frequency of the vibrations transmitted to the cabin via the vibration isolation member and the cabin bracket are not liable to match, even if resonance or the like occurs within the cabin. In the conventional vehicle with a cabin disclosed in Japanese Laid-open Patent Application No. 2001-163267, the generation of a muffled noise is prevented by a configuration in which a weight for vibration isolation is provided, and the resonance frequency of air inside the cabin and the oscillation frequency of the vibrations transmitted to the cabin via the vibration isolation member and the cabin bracket are not liable to match, even if resonance or the like occurs within the cabin.
However, in the conventional vehicles with a cabin disclosed in the documents described above, the cabin bracket is configured so as to have a substantially uniform high rigidity from the fixed member of the cabin bracket to the distal end portion of the cabin bracket, and the characteristic frequency of the cabin brackets has a substantially uniform high value from the fixed member to the distal end portion. For this reason, the characteristic vibration of the cabin bracket as such does not vary even if a damping mass or a weight for vibration isolation is provided. There is therefore a problem in that it is difficult to have configuration in which the resonance frequency of air inside the cabin and the oscillation frequency of the vibrations transmitted to the cabin via the vibration isolation member and the cabin bracket are not liable to match.